Containers of many different types and shapes have been provided for specimens or patient samples that are later mixed with reagents and analyzed to give an indication of a property or condition of the test sample. For example, U.S. Pat. No. 3,905,772 discloses a multi-unit cuvette that is useful in analyzing the blood group of a plasma sample. U.S. Pat. No. 3,607,099 discloses a coagulation apparatus which determines the prothrombin time of a plasma sample placed in a single cuvette to which a reagent is added. U.S. Pat. No. 3,969,079 discloses a cuvette disk having a plurality of sample receptacles arranged in concentric rows. Two receptacles, one from each row, will be radially aligned so that two samples may be analyzed simultaneously. For example, a prothrombin time measurement may be made on each sample, or an activated partial thromboplastin measurement may be made on each sample, or a prothrombin time measurement may be made on one sample while an activated partial thromboplastin measurement may be made on the other sample.